A proposal for next generation security in 802.11 built on changes in 802.11ac

1. A proposal for next generation security in 802.11 built on changes in 802.11ac • 16 July 2012 Authors: Salowey et al (Cisco), Harkins (Aruba)

2. LB188 contains comments requesting the inclusion of updated security options in 802.11ac Number 6198from Brian Hart (Cisco) 6513from Dan Harkins (Aruba) Comment 11ac does not seem to have a sufficiently rich set of security options to meet Suite-B requirements Add support for GCM-256 and Suite B Proposed change Define a sufficient security toolkit for 11ac so that 11ac can meet Suite B requirements, including any transitional measures if required Adopt the changes specified in document 11-12/0711rX, where X is any revision (currently at zero) Now at r1 Salowey et al (Cisco), Harkins (Aruba)

3. It is proposed that TGac consider inclusion of “Suite B-like” security features in 802.11ac in Sept Security mechanisms are evolving due to advancesin computing & cryptographic science 802.11 is missing “Suite B–like” security mechanisms that will be required in the near future 802.11ac should include new mechanisms that support“Suite B-like” requirements • The inclusion of features like AES-GCMP will align 802.11ac with mechanisms used by other standards • The integrity of 802.11 & interoperability will be threatened unless the work is undertaken by 802.11 • A two step process that defines • a “transitional” set of mechanisms • A “Suite B-like” set of mechanisms • Two “minimum Levels of Security” (mLoS) for each step to meet different security needs The proposed path for approval is discussion until September and consideration for inclusion into D4.0 at the Palm Springs meeting Salowey et al (Cisco), Harkins (Aruba)

4. Security mechanisms are evolving due to advances in computing & cryptographic science • Security mechanisms are not static – they evolve over time due to advances in computing and cryptographic science • e.g. DES was deprecated and replaced by AES • e.g. SHA-1 will be disallowed by NIST after 2013, MD5 already is disallowed • The “Suite B” profile defined by the USG NSA defines a consistent set of cryptographic algorithms to provide one of two levels of security • 128-bit: SHA256 for hashing, P256 for key derivation, AES-128 for encryption • 192-bit: SHA384 for hashing, P384 for key derivation, AES-256 for encryption • Similar profiles are likely be demanded by others in the near future • Governments, e.g. US, Canadian and other governments are all known to want a higher bar • Security orgs, e.g. NATO, military • Industry orgs, e.g. financial services & health Salowey et al (Cisco), Harkins (Aruba)

5. 802.11 is missing “Suite B–like” security mechanisms that will be required in the near future Feature IEEE 802.11-2012 What is required for “Suite B-like” security? Encryption AES-CCMP-128 AES-128-GCMP for “128” security AES-256-GCMP for “192” security Note: 802.11ad D8.0 only defines the use of AES-128-GCMP, not AES-256-GCMP MAC HMAC-SHA1, AES-128-CMAC AES-128-GMAC for “128” security AES-256-GMAC for “192” security Hash for PRF HMAC-SHA-1 & SHA-256(only for 11r) HMAC-SHA-256 for “128” security HMAC-SHA-384 for “192” security Salowey et al (Cisco), Harkins (Aruba)

6. The inclusion of features like AES-GCMP will align 802.11ac with mechanisms used by other standards Standard Description IETF RFC 6380 “Suite B Profile for IPSec” • Defines two minimum Levels of Security (mLoS) • 128 & 192 bit security using AES-GCM IETF RFC 6460 “Suite B Profile for TLS1.2” • Defines two minimum Levels of Security (mLoS) • 128 & 192 bit security using AES-GCM • Defines a transitional mechanism using AES-CBC IEEE 802.1AE “MACsec” • Defines use of AES-GCMP 128 and 256 • Using AES-GCMP 128 and 256 IEEE 802.11ad D8.0 “60GHz” • Defines use of AES-GCMP 128 Salowey et al (Cisco), Harkins (Aruba)

7. The integrity of 802.11 & interoperability will be threatened unless the work is done by 802.11 • The 802.11 WG could decide to not undertake this work • The “world will not end” because 802.11i based security will still be sufficient for many use cases • However, increasingly it will not be sufficient in some use cases. • In these situations there is a risk, if “Suite B like” features are not included in 802.11ac, that: • Other organisations will attempt to define variants of the 802.11 standard to meet this need …… threating the integrity of the 802.11 standard • Some companies will define proprietary solutions …… threatening the on-going interoperability of 802.11 based systems Salowey et al (Cisco), Harkins (Aruba)

8. 802.11ac should include new mechanisms that support “Suite B-like” requirements minimumLevels of Security Feature mLOS 128 mLOS 192 Encryption AES-128-GCMP AES-256-GCMP MAC AES-128-GMAC AES-256-GMAC Hash for PRF SHA256 SHA384 Cannot “mix &match” features Salowey et al (Cisco), Harkins (Aruba)

9. A transition to “Suite B-like” requirements should support improved security on older hardware • Not all hardware in existing APs or clients (802.11a/b/g/n) can support “Suite B-like” requirements … • … and yet there is a desire to support “better” security in even these devices • A precedent for this type of support was established in the transition from WEP to TKIP to AES after the “WEP debacle”  • It is known that much existing hardware can support AES-CCMP-256, and the standard should take advantage of this as part of a transition path Salowey et al (Cisco), Harkins (Aruba)

10. 802.11ac should include mechanisms that support a transition to “Suite B-like” requirements minimumLevels of Security Feature mLOS 128 mLOS 192 Encryption AES-128-CCMP AES-256-CCMP MAC AES-128-CMAC AES-256-GMAC Hash for PRF SHA-256 SHA384 Cannot “mix &match” features Salowey et al (Cisco), Harkins (Aruba)

11. The proposed path forward is discussion until Sept & consideration for inclusion into D4.0 in Palm Springs We are here D3.0 LB Brian Hartcomments San Diego Socialisationof proposal Teleconferences Discussion& straw polls Palm Springs Motion oninclusion Let’s select a slot convenient for all interested security folk for discussion Overview of draft changes in11-12-0946r0 &11-12-711r1 Salowey et al (Cisco), Harkins (Aruba)